Based on the research and development of titanium alloys for biomedical applications in China and abroad during the past few years, the metal ions release mechanism from titanium-based alloys, and their pathogenic mechanism and protective coatings and measurements were investigated. A systematic analysis is made of the effect of the corrosion on the metal ions release mechanism from the Ti6Al4V alloy and TiNi shape memory alloy, of the relationship of metal ions with pathogenic mechanism of some diseases, and of the protective coatings and surface modification techniques inhibiting the release of the metal ions. It shows that a large number of surface modification techniques were developed in recent years to improve the biocompatibility and corrosion resistance of titanium alloys and the release of metal ions were inhibited